bisecting fixing commit since 31acccdc877486a649a86d37725a15175fcd5ed6 building syzkaller on cca8798699baeeccbf80af23d234ac19a5d667aa testing commit 31acccdc877486a649a86d37725a15175fcd5ed6 with gcc (GCC) 8.4.1 20210217 kernel signature: 188253f02ef4ac38b1f99cf0a7d562846639e079c654619722d0afffaf439342 all runs: crashed: kernel BUG in dnotify_free_mark testing current HEAD 1e986fe9ad15b8406034c504afc5ae76f0a8e852 testing commit 1e986fe9ad15b8406034c504afc5ae76f0a8e852 with gcc (GCC) 8.4.1 20210217 kernel signature: c7d48b1a1b00f569e14aa5735137ec05a636a72b3c7a32b80663ffb4608988cd all runs: crashed: kernel BUG in dnotify_free_mark revisions tested: 2, total time: 30m3.089040094s (build: 22m43.5175742s, test: 6m42.373532339s) the crash still happens on HEAD commit msg: Linux 4.19.191 crash: kernel BUG in dnotify_free_mark wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready ------------[ cut here ]------------ kernel BUG at fs/notify/dnotify/dnotify.c:132! wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 97 Comm: kworker/u4:2 Not tainted 4.19.191-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready Workqueue: events_unbound fsnotify_mark_destroy_workfn RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:132 [inline] RIP: 0010:dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:126 Code: 78 48 89 fa 48 89 e5 48 83 ec 08 48 c1 ea 03 80 3c 02 00 75 17 48 83 7e 78 00 75 0e 48 8b 3d 04 77 15 09 e8 c7 1f e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 fa 58 e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55 RSP: 0018:ffff8881f49a7c68 EFLAGS: 00010282 RAX: dffffc0000000000 RBX: ffff8881ef3b2c80 RCX: 1ffff1103d80b9e3 RDX: 1ffff1103d80b9ef RSI: ffff8881ec05cf00 RDI: ffff8881ec05cf78 RBP: ffff8881f49a7c70 R08: ffff8881ec05cb50 R09: 1ffff1103d80b96b R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881ec05cf00 R13: ffffffff88142c80 R14: dffffc0000000000 R15: ffff8881ec05cf00 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 FS: 0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000055c071 CR3: 000000000986d005 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fsnotify_final_mark_destroy+0x6d/0xa0 fs/notify/mark.c:213 fsnotify_mark_destroy_workfn+0x1d7/0x390 fs/notify/mark.c:799 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2152 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 worker_thread+0x85/0xb60 kernel/workqueue.c:2295 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Modules linked in: IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready ---[ end trace 68761370135ae514 ]--- wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:132 [inline] RIP: 0010:dnotify_free_mark+0x3b/0x50 fs/notify/dnotify/dnotify.c:126 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 Code: 78 48 89 fa 48 89 e5 48 83 ec 08 48 c1 ea 03 80 3c 02 00 75 17 48 83 7e 78 00 75 0e 48 8b 3d 04 77 15 09 e8 c7 1f e7 ff c9 c3 <0f> 0b 48 89 75 f8 e8 fa 58 e7 ff 48 8b 75 f8 eb da 0f 1f 40 00 55 RSP: 0018:ffff8881f49a7c68 EFLAGS: 00010282 ieee80211 phy15: Selected rate control algorithm 'minstrel_ht' RAX: dffffc0000000000 RBX: ffff8881ef3b2c80 RCX: 1ffff1103d80b9e3 IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready RDX: 1ffff1103d80b9ef RSI: ffff8881ec05cf00 RDI: ffff8881ec05cf78 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 RBP: ffff8881f49a7c70 R08: ffff8881ec05cb50 R09: 1ffff1103d80b96b IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881ec05cf00 R13: ffffffff88142c80 R14: dffffc0000000000 R15: ffff8881ec05cf00 FS: 0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efffeb1e900 CR3: 000000000986d002 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400